PI3K pathway is a site in human cancer cells where mutations most commonly occur and can lead to cell proliferation, activation, and signal amplification.
PI3K kinase (phosphatidylinositol-3-kinase, PI3Ks) belongs to the family of lipid kinases and can phosphorylate the 3′-OH terminus of the inositol ring of phosphatidylinositol. PI3K is a lipid kinase composed of a regulatory subunit p85 or p101 and a catalytic subunit p110, and plays a key role in cell proliferation, survival and metabolism etc. by catalyzing phosphorylation of phosphatidylinositol 4,5-bisphosphate (PIP2) to form phosphatidylinositol 3,4,5-trisphosphate (PIP3), thereby activating the downstream Akt and the like. Therefore, the inhibition of phosphatidylinositol-3-kinase may affect the PI3K pathway, and thus inhibit the proliferation and activation of cancer cells.
Tumor suppressor gene PTEN (Phosphatase and tension homolog deleted on chromosome ten) dephosphorylates PIP3 to generate PIP2, thus achieving negative regulation of the PI3K/Akt signaling pathway, inhibiting cell proliferation and promoting apoptosis. The frequent occurrence of PI3K gene mutation and amplification as well as the loss of PTEN in cancer and the like indicate that PI3K is closely relayed to tumorigenesis.